--[[
Description: task 2.1
Author: DingZY
email: 331646081@qq.com
Date: 2021-06-07 18:46:03
LastEditTime: 2021-06-08 19:26:30
--]]
function F(a, b, c)
    if (a <= 0 or b <= 0 or c <= 0) then
        print("error")
    elseif (a + b <= c or b + c <= a or c + a <= b) then
        print("non-triangle")
    elseif (a == b and b == c) then
        print("equilateral triangle")
    elseif (a == b or b == c or c == a) then
        print("isoceles triangle")
    else
        print("triangle")
    end
end

A = io.read("*number")
B = io.read("*number")
C = io.read("*number")
F(A, B, C)
